Screen for rock crushers



Sept is, 1925. 1,553,693

' E. C. JENSEN ET AL SCREEN FOR ROCK CRUSHERS Filed May 12. 1922Zvwewfors wiwb 4 Patented Sept. 15, 1925.

UNITED STATES,

EARL C. JENSEN AND EDWARD F.

PATENT, OFFICE.

DALTON, or'cnDAn RAPIDS, IOWA.

SCREEN FOR ROCK GRUSHERS.

Application filed May 12, 1922. Serial No. 560,443.

rock and stone, more particularly stone from gravel pits, and the like,in which the larger masses are mixed with small stuff, like pebbles andgravel. I I The object of the invention is to produce a simple andeflicient screening apparatus, whereby this finer stuff may be separatedfrom the rest, and only larger stones or rock masses be delivered to thecrusher, thus relieving it of much needless work, and increasing itselficiency.

In the operation of a stone crusher much of the material as taken fromthe quarry or pit need not pass through the crusher at all, being of acharacter admirably suited for concrete, or for road buiding, and thelike. If passed through the crusher, beside choking the crusher withneedless material, it tends to deteriorate the quality of the crusherproduct, which should be all broken stone if the mass is to be uniform,clean and sharp. The apparatus herein described is designed to make thisseparaQ tion economically, and in a very simple man ner, as will appearby the. specifications and claims following, in connection with theaccompanying drawing, in which:

Fig. 1 is a side elevation of apparatus embodying our invention as inuse. Fig. 2'

is a plan view of the screen, with some of its connected parts. Fig. 3is a fragmentary and sectional View, showing the upper and lower ends ofscreen-bars and frame, sideboard, and a section of a baflie-board hungfrom the side-board. Fig. 4 is a fragmentary view in perspective,showing means for imparting vibration to both sets of screenbars. I

In the drawing, the numeral 5 denotes a rock-crusher, driven by a belt6, and provided with the usual heavy flywheel 7, which C. JENSEN and ishere shown belted to a smaller fly-wheel 8, of which one is supposed tobe mounted each side of the machine. The fly-wheel shaft 9 is mountedinbearings 10 on a frame 11,

which is a little higher than the body of the crusher when set inworking position. To thls shaft it attached a sprocket-wheel 12, whichconnects by a chain 13 with a smaller sprocket 14; on a cranked shaft 15mounted in bearings 16. The cranked ends of th1s shaft connectby/connecting-rods 17 with a cross-shaft or rod 18, to which the movablebars of the machine are secured. In Fig. i the end of the shaft is showndoubly cranked, and connecting-rods 17 and 17 connect with both sets ofscreenbars to give them alternating motion,

though in practice the movement of gang is ordinarily suflicient.

A rectangular screen-frame 19, may be of wood or metal, is attached tothe main frame inean inclined position as shown. Preferably it is hingedat the lower end,

slotted at 22 and secured by, bolts 23; For

the same purpose the connecting-rods l7 which on' a rod 20, and itsupper end is supported 1 may be made oftwo parts, with'slottedconnections at;17 Flaringside-boards 24 retain the material as receivedfrom the pit or quarry. chute 25. A bathe-board 26 hung from thesideboards, and provided with a. restoring spring 26, serves to arrestthe flow of material, so that all of it is subjected to the action ofthe screen, instead of running down it too rapidly and into the crusher.Vhen in operative position the lower end of the screen overhangs themouth of the crusher as indicated.

The screen is composed of a double gang of'alternatinglongitudinal'bars, 27 and 28, respectively. These, are hinged togetherat the footby a hingerod 29, with interposed space-blocks 30. Longerspace-blocks 31 separate the bars 27, which are tied by a rod '32. Thebars 28 may usually be secured rigidly to the screen-frame, and for thispurpose their ends are provided with downwardly turned lugs 28 providedwith setscrews 28". When thus rigidly attached to the frame,space-blocks for the upper ends ofthese bars may be dispensed with. Whenthi gri S ade movable, as shown'in Fig.

. readily understoot.

4, the space-blocks are set'low enough to allow the bars of the othergrid to swing at least to the level of the grid 28. The bars are soconstructed that when assembled in operative position the screenpresents to the material deposited upon it a series of rows of squareholes of the desired size to properly riddle the material. is effectedby providing each screen-bar with lateral lugs, 33, the lugs of one gridoecu-V pying a space midway between two lugs of the other grid. Theopenings thus formed for the passage of material should be larger belowthan above, so as to give clearance to stones working into them, andpermit them to drop without clogging the screen, as indicated in Figs. 3and A.

The operation of the apparatus will be Rotation of the cranle shaftproduces a short rather rapid up and down vibration of one (or both)grid, hinged at the lower end. This shakes the smaller stuff through,the larger masses sliding down, over the lower end, and into the mouthof the crusher. Being formed of rigid bars, the screen is strong enoughto resist the wearing and smashing effect of the delivery of heavymaterial thereon, and it is therefore more serviceable than a woven wirescreen. The movement of alternate bars of the grids with respect toadjacent bars, also tends to thoroughly sift the material, and toprevent the lodgment and clinging of stones in the holes as they aredisposed to do in a screen or grid with fixed reticulated parts.

It is preferred to make the grids of gangs of separate bars andspace-blocks bolted together. This lnakes it possible to easily insert anew bar, should one break, without having to replace the whole grid, andalso makes it easy to change bars of one spacing to others with largeror smaller spacing, as desired.

This

Having thus described our invention, we claim:

1. A pebble screen, comprising a pair of grids having longitudinalalternately interposed bais spaced apart, and having lateral lugs-nearlyspanning the interspaces, and alternately disposed lengthwise, thespaces be-- tween lugs of the respective grids forming holes for theescape of material, a pivotal connection of one grid with the other atone end, and means for vibrating one grid with respect to the other. i

2. A screen for-pebbles and the like, comprising a pair of grids withparallel, interposed and openly spaced bars, having lateral lugs nearlycrossingthe in-terspaces, and alternately disposed to form substantiallysquare openings in the screen, a pivotal connection at one end to permitone or both grids to move to and fro, and means for i1npartingreciprocating movement to one of the grids.

3. A screen for stone and thelike, comprising a screen-frame, a gang oflongitudinal bars secured thereto, a grid having alternately interposedparallel bars hinged at one end with respect to the fixed gang, asupport for said screen, and means connecting with the grid forimparting reciprocating movement to its free end.

4. In a screen for stone and the like, an inclined screen formed oflongitudinal bars, alternate bars being hinged at one end, a supporttherefor, a rotary crank-shaft, endwise adjustable connecting rods totransmit motion from the crank to the grid of movable bars, andadjustable supports for the upper end of the screen, whereby itsinclination may be shifted.

In testimony whereof we afiix our signatures.

EARL o. JENSEN. EDWARD F. DALTON.

